This invention relates to paneling, specifically to an improved wood panel attachment and alignment system for interrelating adjacent wood panels.
A problem addressed by this invention arises from attaching and aligning paneling. Unresolved problems with some currently known solutions call for creating new ways of mounting panels to a wall surface and to trim the panel edges. A new system is needed for working with different panel versions that also accommodates different panel sizes and termination conditions. The perimeter of the panels needs a new trim element to protect the sometimes vulnerable edges of panels and to visually frame them. Panels could be expected to cover some wall surfaces and structures that would span multiple panels in multiple courses. Another consideration early in the process was the desire to avoid visible fasteners when attaching the panels to the wall surface.
In addition to those problems presented when hanging wood panels, there is also a dimensional change problem. Wood is a hygroscopic material that in high humidity picks up moisture and swells while in low humidity releases moisture and shrinks. Uncontrolled extremes of relative humidity, whether low or high, are likely to cause problems. While a user can clearly see the damaged wood paneling from subsequent dimensional change in wood, the responsibility for preventing and correcting the problem is not clear. The manufacturer of the wood paneling may deny responsibility pointing to the inherent natural property of wood to change dimensions. Other times it can be unclear whether or not the cause and responsibility for dimensional change problems in wood products was the result of improper design and whether it is the responsibility of the designer or architect or specifier. Also, the question of cause and responsibility for dimensional change problems in wood products resulting from improper relative humidity exposure during site storage and installation may not end with the general contractor. Responsibility for dimensional change problems in wood products resulting from humidity extremes after occupancy may also rest with building engineering and maintenance. AWI AWMAC WI, Architectural Woodwork Standards §2, at 44 (1st ed. 2009). What is needed is to further address the subsequent dimensional change in wood panels.
A variety of panel hanging systems have been known in the art for quite some time. For example, a panel may simply be attached using nails or screws through the face of the finished wall panel into the wall framing or into blocking installed specifically for this purpose.
Another example is an interlocking extruded aluminum wall cleat system. Cleats fastened to the back of the wall panel engage cleats fastened through the wall surface into the wall framing or into blocking installed specifically for this purpose. The cleats are typically constructed of extruded aluminum. Blocking is typically installed by others. Shims are installed behind wall-mounted members. An instrument is required for proper field layout to level and to plumb panels. The number and placement of cleats must be determined in consultation with an installation team. AWI AWMAC WI, Architectural Woodwork Standards 626 (1st ed. 2009).
These and various other options for attaching the panels to the wall were considered but were eventually found wanting. Screwing or nailing through the face of the panel were options that were rejected immediately. Using an extruded aluminum “Z-clip” is an option common in the industry and was evaluated for this purpose. However it can require careful alignment of the two mating clips when installing as well as an added expense to purchase the hardware. It needs to be attached to the back of the panel with screws, and so sculpted panels that vary in thickness present the possibility that these screws could penetrate through the face of the paneling. Using thicker panels was considered but rejected due to some of the disadvantages of that option including higher costs for materials and shipping, greater weight to support on the wall and greater difficulty in handling through the manufacturing and installation processes.
A related technique is the use of “French cleats”, typically two wood strips with mating beveled edges. An advantage that this has over the use of Z-clips is that it can be glued to the back of the panel eliminating the screw-through disadvantage. Unfortunately, additional material and labor to produce it are required. Still another disadvantage with both of these options, Z-clips and “French cleats” is that the panel must be spaced off of the surface of the wall by their inherent thickness, and therefore require deeper trim elements at exposed panel edges in order to hide their use.
These currently known indirect application methods and devices suffer from several unacceptable disadvantages for these presented problems and call for creating a new solution. Additional hardware or mounting blocking must be purchased or manufactured. Too much time is spent laying out the installation. The entire assembly extends too far from the wall requiring large edge trim elements.
How to join and trim custom wood panels pose additional challenges. Trim around the perimeter of the panels was explored in many ways. Some currently known examples include a lock miter outside corner, a splined miter outside corner, a solid wood outside corner, a solid wood reveal outside corner, a solid wood reveal inside corner, and a cut- to-fit inside corner. Additional joint and plant assembled joinery issues arise from joinery standards in the absence of specifications. Tightness of plant assembled joints between laminated components must address maximum gap and flushness variation factors. AWI AWMAC WI, Architectural Woodwork Standard 179-181, 547 (1st ed. 2009).
Prefabricated aluminum extrusions to be used as trim elements were considered at length. Many of these come with concealed mounting strips, which satisfy the hidden fastener requirement. The availability of multiple shapes of extrusion fit in well with the variety of panel patterns and finishes giving lots of design options. The options explored for installation of these extrusions were varied as well. One method was to attach the trim to the panel prior to mounting. Another method involved attaching the trim to the wall first creating a frame into which the paneling would be hung. Another method would be to hang the paneling first and then mount the trim to the wall around the paneling. While these extrusions were attractive and available in multiple finishes there was a desire to match the panel's finish exactly and to be able to create custom profiles for the trim. This concept led to experimenting with painted wood for the trim elements. Very early on the use of an off-the-shelf blind fastener such as a “Klick” fastener manufactured by Friedrich Knapp Gmbh in Austria having U.S. Pat. No. 6,186,698 was experimented with as a means of blind fastening the trim. The dovetail-shaped groove into which this fastener clips is easy to machine into the mating components and the relationship between panel and trim is consistently controlled by this pre-machined relationship. Combining this method of trim attachment with the rabbeted edge of the panel for screw attachment proved to be a harmonious solution to both issues.
Envisioning this treatment around the perimeter of each panel raised an issue of how to treat the joint between adjacent panels. Initially several versions of an intermediate trim element were explored. Again, this trim could be attached using the Klick fastener, thus hiding the attachment screws between panels. The need to allow the panels to expand and contract at this joint complicated this concept. The trim could not be allowed to attach to both of the adjacent panels without allowing movement. This led to experiments involving the machining of a slot very close to the panel's edge that could deform and absorb the expansion of the adjacent panel. Contraction of adjacent panels would simply pull them away from each other, the gap being covered by the intermediate trim element. An inherent advantage to this idea is that the panels would be installed tight to each other without the need for the installer to set the expansion gap. Several iterations of this expansion-absorbing slot were worked out. It was during this process that the idea was put forward of using the slot for the Klick fastener to also serve as the expansion-absorbing slot.
Also at this time the idea of one panel overlaying its neighboring panel came into play. If the first panel could be screwed on, then a portion of the second panel slipped beneath the first one's edge, then there would be no need for screws in that edge of the second panel. This was the genesis of the “projection & recess” concept.
Further experimentation with this concept led to the alternating use of projections and recesses to mutually engage both adjacent panels. This type of symmetry meant that the paneling could be installed the same way starting from either the left or right end of a run of paneling. This affords flexibility to the installer, which he might not otherwise have. This also allowed the panel to be universal in fit when rotated 180 degrees. Assuming the sculptural pattern on the panel's face was similarly symmetrical, this meant that there need not be a defined top or bottom to each panel.
Next to be refined was the shape of the serpentine edge of the recesses milled into the back of the panel. A bulge was introduced to bear against the web formed by the expansion relief slot of the adjacent panel. The bulge serves to index the panels' relationship when installed. When a panel needs to expand, this bulge deforms the web allowing the panel to expand without buckling.
This concept of interlaced projections and recesses eliminated the need for the intermediate trim to cover the joint. This has the advantage of allowing the pattern on the faces of adjacent panels to flow across the joint uninterrupted. The edge design in its final form can be machined on all edges if the paneling needs to be multiple courses tall. Otherwise it can be machined on only the vertical edges if that suits the application best. The projection serves double duty as a screw-mounting protrusion and as a surface area to mount perimeter trim using the Klick fasteners. Perimeter edges need not be machined any differently than meeting edges.